Looks like they have been around for awhile and they use good stuff internally, even on the "package" motors.
Regarding NOS, the new systems are not like the 'old days' where the fuel system had to be richened up in order to run the NOS....all of the modern systems introduce additional fuel along with the NOS to avoid detonation.
On the new systems, you can hit the button below WOT and not do damage, because the system is adding fuel as well. Try it on empty tanks and you will see how fast it will flood the motor.
You do have to be sure that the engine components are capable of the additional hp. For instance, GM does not recommend that a ZZ4 bottom end be continually subjected to over 500hp.....so it would be foolish to put a 200hp shot in a ZZ4 and not expect a problem somewhere. So if you were going to build an engine from the ground up, just make sure that the rods, pistons, etc. will handle the advertised hp plus any NOS that might warm your blood later on.......or simply plug a NOS system on to your current motor....remember the grin you got from the converter???? Double that with a shoot of the 'juice'.
And it's cheap :lol: